Tire building machine



July 29, 1952 H D, STEVENS 2,605,197

TIRE BUILDING MACHINE linventor Boue :0, Sfvms (Ittomegs July 29, 1952 H. D. STEVENS TIRE BUILDING MACHINE 9 Sheets-Sheet 2 Filed April 27, 1950 INVENTOR. Bora twms y@ July 29, 1952 H. D. STEVENS 2,605,197

TIRE BUILDING MACHINE Filed April 27, 1950 SSheetS-Sheet 3 l ff @TTOP//l- July 29, 1952 H AD. STEVENS 1 2,605,197

TIRE BUILDING MACHINE Gttornegs July 29, 1952 H. D. STEVENS 2,605,197

TIRE BUILDING MACHINE Filed April 27, 195o 9 sheets-sheet 5 July 29, 1952 H. D. STEVENS TIRE BUILDING MACHINE Filed April 27, 195C 9 Sheets-Sheet 6 Snvntor Horam Qlemms July 29, 1952 H. D. STEVENS 2,605,197

TIRE BUILDING MACHINE Filed April 27, 195o 9 sheets-sheet 7 INVENToR. Hema I). Steven BY ZZV@ A TMF/YH@ July 29, 1952 H. D. STEVENS 2,605,197

i TIRE BUILDING MACHINE Filed April 27, 195o 9 sheets-sheet e I N VEN TOR, Horan n shunts July 29, [952 H. D. STEVENS TIRE BUILDING MACHINE Filed April 27, 195o 9 Sheets-Sheet 9 :inventor Horace 35,' Stevens attorneys Patented July 29, 1952 TIRE BUILDNG MACHINE Horace D. Stevens, Sarasota, F1a., assignor to y The Firestone Tire & Rubber Company, Akron,

Ohio, a corporation of Ohio Application April 27,1950, Serial No. 158,483 v 'f 18 Claims. 1,v

This invention relates to a tire building machine, and more especially it relates to apparatus for fabricating pneumatic tire casings by the flat band method, and more particularly to ply stitching.

In the prior art, as exemplified in my Patent No. 2,381,379, tirebuilding drums had an inwardly curved neck or apron on their end rims,r

against which the bead Was laid, so that the bead lay at an acute angle to the drum axis. In building a tire, the first two plies wereV rst turned inwardly on this apron, the bead was then applied, and the iirst two plies were then turned up to encase the bead. In order to initiate this turn up it was necessary to employ a nonrotating, plow-shaped element which was insertable between the iirst ply and the apron. Thereafter, some convenient form of roller stitcher Was employed to complete the turn up. The plow-shaped element has been found to be unsatisfactory for several reasons,'among which are the undesirable wrinkling of plies and damage done to the ply fabric due to chang. According to the present invention, the aprons on the drum rims are eliminated, the plies are turned down across .the drum rimsto a position radially ofthe drum axis, and turn up, roller stitchers are provided which reach into the open ends of the drum to pick up the plies.

The chief object of the invention is to conserve time and manual labor in the manufacture of tire casings of the character mentioned. A further object of the invention is to provide a tire building machinev in which hand stitching is avoided. Yet another object is to provide machine stitching of tire plies in which Wrinkling and chang are avoided. In greater particular, it is also an object to provide for machine stitching of tire plies in close quarters, as in the beadcovering operation.

The apparatus of the invention comprises a power-driven, reversible tire building drum of the type which is collapsible by means of a brake on the-drum shaft and lhaving bead-applying rings movable axially of the drum, on either side thereof. Endless belt spring stitchers are provided in front of the drum, for certain ply-turning operations, and novel, cone or acorn type stitchers are provided rearwardly of the drum for other ply-turning operations, The latter stitchers are mounted on a generally vertical axis foi` swinging motion into and out of the end openings of the drum, being arranged for clearing the rim of the drum in this movement, and are also of dual construction to-iperform different types of stitching, automaticallyselective in accordance with direction of drum rotation.

In greater particular, the invention is described in the following specication and' illustrated in the drawings, in which: 1

Fig. 1 is a front view of a tire building machine incorporating principles of the present invention,

Fig. 2 is an end view ofthe stitcher mechanism at the rear` of the tire building drum,

Fig. 3 is a rear view of the stitcher mechanism of Fig. 2 taken-onvthe line 3-3 of Fig. 2,

Fig. 4 is a sectional -view taken Qn the lline 4 4 of Fig. 3, v v v Fig. 5 is a sectional View taken on the line 5--5 of Fig. 3, i

Fig. 6 is an enlargedview of the upper portion of the stitcher mechanism of Fig. 2, showing one phase of operation thereof in its relation to direction of rotationl of the tire building drum,

Fig. 7 is afragmentary view showing the roller stitcher of Fig. 4 in' another phase of operation thereof in its relation to the' direction ofV rotation of the tire building'drum,l

Figs. 8 to;13,linclusive, are fragmentary views showing successivephases of operation of the roller stitcher of Figs.'2 `to 5 andthe ply-turning operations accomplished in'each case;

Fig. 14 is a fragmentary view ofA a modiiied form of roller stitcher for useon the mounting shown in Figs. 2 tof5,

Fig. 15 is an end view of a modified base mounting for the rear stitchers, and

Fig. 16 is a partial rear View of Fig. 15, 'taken on the line IG-IB of Fig. 15.

Viewed as a whole, the tire building machine comprises a power unit I for driving a collapsible drum 2, a base structure 3 supporting the stitching, trimming and bead-applying units, and a supply structure 4 by means of which the various tire elements, other than the beads, such as the Y plies, chafer strips, and tread strips, are made readily available to the operator.

Drum 2 is mountedon a cantilever shaft 6, for rotation therewith and shaft. 6 is-rotated by a prime mover (not shown) inthe power -unit I. A bead-applying ring 'I is freely rotatable on a collar 8, which is keyed toshaft 6 in a slot 9 so as to be movable axially thereof, to approach drum 2 in applying a bead.k Collar 8 has a split ring I I engaged ina groove'in itsV periphery and ring I I has a downwardly extending arml I2 connected to the piston rod I3 ofA an air cylinder (not shown) in unit I, so thatthe ring] may be moved to and from the drum. A handle I4V con'- nects with a brake (not shown) which is associated with shaft E and is operative to collapse or expand drum 2 as required in the tire building process.

All of the foregoing elements include structure known in the art and, therefore, require no minute description.

The supply structure4 may be of any known or preferred construction and comprises a hous-v ing which maybe of the turntable type mounted on the base 23. In this structure are journaled pairs of rolls 2 l 22. A supply of ply material andseparating liner is wound on each roll 2! and the liner in each case is rewound on an adjacent roll 22, automatically, as the ply material is'payed out from roll 2|.

An apron 24 gives support to a ply as it is led from its roll to the drum, the apron being'hingedly mounted on unit 4 so as to clear adjacent machinery when the supply unit is rotated, if the'turntable type of supply mechanism is to be employed.

Other conventionalfmechanism may be included in structure 4 fori supplying chaferI strips and tread stock to the drum.

The mechanism supportingk the tire building tools is mounted on a floor plate. 3l, together with the power unit I. These tools comprise the outer bead applier, a pair of turn-down ply stitcher units'located infront of the drum, and a pair of combined', turn-down and turn-up stitchers located rearwardly of the drum. Also carried on the base are various foot switches, limit switches, air cylinders and atirner, all presently to be referred to as the description proceeds.

The bead-applying ring for the outer end of the drum, shown at 32, is carried on-an upright arm 33 mounted on a plate 34 slidably mounted in undercut ways in a horizontal plate 31 supported on a framework comprising a bed plate 33 and upright plates 38, 39, 49. This type of support for the bead ring holder, comprising a long, upright arm, may res'ult in slight misalignment in placing the bead on the drum.V Therefore, centering guide means for the bead ring holder are provided in a female, tubular element 35 carried at the'center of the bead ring holder, which is receivable on amale element 49 carriedon the center shaftof drum 2 in coaxial relation there-V to. The ends of'elements' and 43 will preferably be beveled, to permitV initiation of their telescopic engagement in cases where their axes A pair of tread-stitcherY discs 44, located beneath drum 2, are rotatably mounted in a pair of blocks 4B, carriedr on piston rods of air cylinders 41 whereby the discs may be movedr upwardly into contact with a tread when the latter is in place on the drum.

Air cylinders 41' are each' attached to a block 48, threaded on a ,screw 49, journaled in support plates 38,133, 40, the screw being oppositely threaded on each' side of plate 39. Screw 49 is u rotated bya motorlil and gears 45,59 and, .in turning, effects separating movement of stitcherv discs 44, axially' outward of the drum in one direction of rotation. of the screw, and return thereof in the other direction of rotation of the screw'. During 'such axial movement'blocks 48 are supported by rollers l, running between rails 52, 53 carried by plates 38, 39, 49. -A switch 54, carried on rails 52, 53, is operated by a portion of block 48 to reduce the speed at rwhich tread stitchers move during that portion of their travel when the discs are moving off the inner crest of the tread strip. A switch 55, similarly mounted, stops travellof the tread'stitchers and'initiates their lowering and'their return by suitable controls which need not be described in detail.

f The pair of stitchers located in front of drum 2-are described and claimed in my co-pending application, Serial No. 158,482, filed April 27, 1950, nowPatent No. 2,581,933, dated January 8, 1952, and reference ismade thereto for more detailed description. For purposes of the present specification, it suflices to. point out that the stitchers thereof, and a second similarly mounted spring 6I with a' backing roller under its span between. the sheaves and adapted to pass over the edge of the drum to turn down the plies.

In the present machine, the inwardly directed.

apron,.or neck, on the rim ofthe drum 2 has been eliminated and the rim of the drumis perpendicular tothe drum axis. This is important, not'only in thev employment of the spring stitcher just' mentioned but also'in the operation ofvl the novel stitcher located rearwardly of the drum, and involves a` departure in the manner vof laying the bead inthe tirebuilding process. A third element of the front spring stitcher comprises a roller stitcher E2 mounted for swinging movement on an arm 53. actuated by air cylinder 54 on unit 56. Roller G2 is intended for turn-down of the third and fourth plies and is used instead of a spring stitcher to enable higher drum speed.

One of the two stitcher units located rearwardly of the drum is shown in detail in Figures 2 to 4. The two back stitcher units are identical, except for being oppositely arranged for work on oppositel edges of the drum, and, therefore, only one need be described. The stitchers are carried on a pedestal 63 extending across the rear of the machine. the pedestal and-at the ends thereof brackets 61 are secured by bolts 63. A shaft 69 is supported in bores in brackets 61 and journaled thereon are brackets 1i, at each end of the machine, and a similar b-racket 12, at a midway point, the brackets being secured together by a shelf 13 secured to the undersides thereof by bolts 14.

A cast block 16 (Fig. 4), which serves as a support and journal mounting for the stitcher unit, is also carried on shaft 69 and is slidably adjustable along this shaft to accommodate various drum lengths. The-block 16 has a slot 1'! (Fig. 4) received, for sliding motion of the block. cn a bar 13 of rectangularA cross section, which is secured in slots 19 in brackets 1l, 12 by bolts 13. Block 15 is thus arranged to rotate in unison with brackets 1l, 12 and shelf 13, and may be` adjusted along shaft 69 and bar 13 by means of a ybolt 83 journaled in bracket 1|, threaded in block V13, and provided with a lock nut 85 on the inside of bracket 1 I.

The mounting of the stitcher support block To the top of' adjustment of the inclination of the stitcher with respect to the particular drum being used, and, as will be detailed hereinafter, the angular position of the stitcher is important for operation of the novel stitcher roller of this invention.

For holding the block16 in adjusted angular position on shaft 69, there is provided a strap 8|, which is secured to shelf 13 by bolts 82 and has a downwardly bent portion 83 with a bore 84 received on an adjusting screw 86'. The'latter has an eye 81 at one end, swiveled on a pin'88, carried by a pair of lugs 89, secured to the upper side of casting 66. Strap arm 83 is held in the desired position on screw 86 by meansof a pair of nuts 9| and thus the stitcher-mounting block 16 is locked in the desired angular position.

Referring to Fig. 4, it will be seen that the stitcher unit is mounted in block 16 by means of a shaft 92 rotatable on needle bearings 93 carried in the block; Shaft 92 is threaded, at 94, at its upper end and, at 96, near its lower end, and is secured against axial motion relative to block by means of an upper nut 91Y engaging threads 94 and a lower-nut 98 engaging threads 96. Between lower nut 98 and the block is a washer 99 and a ball bearing unit IOI. Between upper nut 91 and the block are hub |02 of a crank arm |03, a spacer sleeve |04, hub |06 of a worm wheel |01, a ball bearing unit |08, and a washer |09. Hub |02 is keyed to shaft 92 at III'and hub |06 is keyed to said shaft at I I2.

For rotation of stitcher unit'shaft 92, worm wheel |01 is driven by a worm II3, mounted on a shaft I I4, which is journaled in a pair of bearing blocks ||6, secured to the top face of block 16 .by bolts I| 1. Worm shaft 4 has one end extending beyond its bearing block and on the end is keyed a pulley |I8. A motor |I9 drives pulley ||8 through a belt |2|. The motor is secured by bolts |22 to a mounting plate |23, which in turn is secured to the back face of block 16 by bolts |24. The latter pass through openings |26 in plate |23, which are of suitable length to permit sliding adjustment of the plate to vary the tension on the motor belt.

Drive is communicated to the other rear stitcher unit through a telescopically arranged shaft system which permits adjustment of the two stitchers axially of the drum. For this purpose, the inner end |21 of worm shaft |4 is enlarged to fit within the end of a drive tube |28, to Awhich itis secured by spline keys |25, for rotary drive, and also by a set screw |29 to prevent axial movement of tube |28. A mating shaft |3| is received in tube |28 and the two are secured, for transmission of rotation, .by means of a pin |32 laterally disposed in shaft |3| and extending on either side thereof, and engaging diametrically opposite longitudinal slots |30 in tube |28, which connection permits relative axial motion of the tube and shaft as the stitcher units are adjusted axially of the drum. n y

Shaft |3| has a reduced portion vI-M, generally similar to shaft ||4, which is likewise mounted in bearing Yblocks (not shown) and carries a worm ||3' for driving a worm wheel on the other stitcher (not shown). Shaft portion ||4 carries a gear |33 (Fig. 2) engaging a gear |34 connected with a timer |35 through a shaft |36. The timer, which is of conventional -construction, and therefore need not be described in detail, governs the various motions of the rear stitchers.

Referring again toy shaft 92, it will be seen that it is axially bored to provide a passage |31 for conveying air under pressure vtothe upper part of the stitcher, for a purpose presently to be explained. The air `is introduced, from an appropriate source, through a conduit indicated generally at |38, which is threaded into 4the side vof a sleeve |39, surrounding a reduced extension |4| on the lower end ofr shaft-92, a washer |42 being provided between the' sleeve and the threads 96. Sleeve |39 has aninwardly directed flange |43 at its upper end. snugly tted on extension |4|, and a lower cap` |44 is also fitted on the extension, being secured thereto by a pin |45, and the cap has a ring flange |46 mating with a rabbeted groove in the lower, outer edge of sleeve |39. With thisarrangement, sleeve |39 defines an annular chamber |41 about extension I4I, `which receives airv from conduit |38. Thelower end of bore |31 is plugged, as at |50, and alaterai bore |48 provides air communication `between the bore and annular chamber |41 in allipositions of rotation of shaft 92. To avoid leakage of vair from chamber |41, there are provided an upper.

supporting standard' |56. V"A strengthening webA |55 connects 'sleeve'I5'4 and topi |53.' Sleeve |54 is secured by a pin |51- tothe enlarged head |58 of a journal shaft |59 mountedron ball bearing units |6|, I 62, secured in the sleeve `I 54. A pinion I 63 is keyed to the lower part of shaft'l59, as at |64, r'and is secured by a nut I 66 on the threaded lower end of the shaft, 'washers |61, |68 being provided 'on respective 'sides of the pinion. The pinion is actuated, to turn the standard |56, by means ofa rack |69, secured-to the piston of an air cylinder |1|, and guided in its sliding motion between the tines -ofra fork |12, boltedat |13 to the underside of crank arm |03. The air cylinder is bolted at |14 to a lateral arm |16 of the flat top |53 of the crank arm, supporting arm |16 being strengthened by a web |60. Air cylinder |1| is energized through a conduit I11'having a fitting |18 threaded inthe wall of hub |02 and communicating with a'. lateral bore |19 in shaft 92, leading tothe axial bore `|31 therein.

Air cylinder |1| is single-acting'to move rack |69 inwardly of the plane of Fig. l5', against the resistance of a helical spring 8| surrounding standard 56. 'I'he spring is anchored at one end to a screw |82 on standard |56 and, at the other end, in a bore |83 in a collar |84, secured by a set screw |86 to a shoulder |81 on sleeve |54. Upon release of pressure from the air cylinder, standard |56 is reversely rotated to itsnormal position by spring |8I.

The stitcher roller, `or acorn stitcher (Fig, 6) indicated generally'by the numeral |88, is rotatable on a shaft |89 secured in a bore |9| in a block |92 by a set screw |93. Block |92 has a stub shaft |94, rotatably mounted in a bore in the flat, upper end |96 of a curved arm |91 of standard |56, and has a reduced end `threaded to receive a securing nut |98, shaft |94 being free to rotate in its mounting. Block I 92 has an oblong opening |99 and threadedly receives a pair of adjusting screws 20|, 202, adapted to pass into opening |99 and having lock nuts 203, 204.

A pin 206, extending laterally from the flat portion I 96,- extends into openingV |99 andthus limits the extent; ofcloclriviseland jcounterclockwise' swing '0f' block; L92 fand;v stitoherf |83; as; 'deterrfy minedA bythe settingA of screws: 201, 2|J,2. -Thelimiting'. Values of inlinatipn; of; stitoher 88 L are entlyrotatable about'V said shaft; and4 section, 298 l being movable. axiallyy of the; shaft, while section 281 is xedagainstmotion axially of the shaft and limits outward sliding "offsection 2 03;. j

End section 207; comprises;.a ring 268 having 2|2V receivable,- in the. open end. of' section 2,63; Ring.: 2,09, is secured; to the Vouter'. race of' anti.- frictionbearings 2g|-3fby=zmeans of-screws 2| ll' and an inner clampingring Zlfgandztheinner. raceof the. blearingsissecuredpn aled'uced vend or shaft |89. by means.'V of afwasher" 2,|.'|` and a central screw 2.|8 threaded into-shaftA |89. l

The larger section 21H3A ,of the stitoher is also of generally ring form,andihas.anfaxialcounterf bore, 2| Q re'ceivingthe outen races: oranti-friction bearings22l., 222, the inner races .ofiwhich aresnugiy lined on shaft iemand sud-ame merealong. The 'bearings are spaced; apart 'by' a' sleeve 226..;andl the entirelbearingY ,assembly `is locked inplace. inythestitcherby the heads of screws 224 threaded; into the; recessedrear facev of thisstitcher-sectioni.. 1

Another oountelbore."2l5Y inthe. front end of roller; 208 isadaptedto receivethe iskirt;.2| 2 of roller 201 and hasv aourved opening 22Tl Vat its front rim to receiveV bead 2| |in mating'relation,

so that the two rollers mergefin outer profile, This is the poand form, in effect, one roller.A sition which roller 208v normally assumes, under the urging of a coil spring 2128V surroundingshaft |89, andj acting-againstbloclrgl92-and a spacerf ring 229 located behind'thev innerl race. of vbearing222. I g .7..

Preferably; the large s-titcher element''lidgwill have a roughenedA surface, as-by'knurling |96; so as vto alford'more positive contact withthe plies and avoid slipping, which might result in pleats or folds. Axially: directed flutes |95 have also proved beneficial in', attaining a smooth stitching operation,free;from faults. In general, various s chemes'andrpatterns in the roughening of the stitcherf surfacewill be foundbene-Y cial. ff'

In the building of -ai tire, the -operatorwill rst place av bead oncarrier` l-and vmay .at such time, orV later in the process; place a bead-'onv carrier 32. The end of the Afirst ply-is thenled from-its supply roll to drum 2f and pressed v,into A.adhesive engagement therewith. The operator'then steps on a foot switchl |38 leading to suitable 'controls whereby the drum. is: rotated 360, drawing the plyy intoy Vposition on the drum, and thereupon ro-y tation of the drum ceases automatically.V rThe edges of the plies are Athen brought` together in abutting relation to formfaY complete plyfcircle,

and the-processis repeated for-they second. ply.

Fig, 8, wherein the first 1 and 32 are actuated bytheir respectiveair cylinders toy lay the beads overv the-edgeof the drum, vonto second ply 42,32, as shown in Fig. 8, the bead being indicated by 233. g

Turn-up of the firsttwoplies, that is, encasement of the bead, is accomplished by the rear stitchers, which have just been describedin the following manner. After the bead is applied, motor IIB is started, through an appropriate switch, and, through worm ||3 and worm wheel |37, crank arm |23 is swung from its normal position of rest, asl viewed in Fig.` 8V where it lies outside of the periphery of the drum, clockwise, about the axis of shaft 92, to a position ywhere stitcher |88 is located interiorly of the `drumtl1eA rotation being interrupted by appropriate controls in the timer |36. In order vto prevent over,- running of the stitcher unit in this rearward swing, a safety device is provided in a limit switch23 carried on a guard element 235 which shields the worm wheel llll', the switch being contacted byV a dependent arm 2,31 on crank arm m3 of the stitcher to stop motor llif'for any reason the crank armipassesbeyond the Vproper limit of travel. y l

In this movement the stitcher is merely being positioned for the turn-up operation,v and its path of movement is such as tov clearthe Vfree edges of the plies. Therefora, atthe'end ofv this inward swing, the stitcher is positionedin spaced relation to its working lpoint, as seen in the dotted .line position in Fig. 8, and it'must be brought vinto contact withtheworkhto accomplish the turn-up. The required movement of the stitcher to its working position is accom, plished by rotation ofgstandard |55 in sleeve ld. Thus, when the crank armhas reached its,l inward limit of travel, the timer initiates air pressure through shaft 92 to air cylinder ,lllr and standard |56 rotates in its mounting, againstthe pressure of spring Il, to a position, as shown'in Fig. 9, where it urges the pliesl against the tire bead. Prior to this action, the drum has been then actuated to carry-spring set in rotation in the direction indicated by the arrow in Fig. 6 by means of a foot switch 23%. After contact by the stitcher, motor H9 is set in rotation by the timer, to return crankarrn |63 to its normal position outwardly of the drum.

The axis of shaft 92 is on a line substantially tangent to the drum and generally in the plane of the bead, so that stitcher |918 remains in close, pressure contact with the bead, through theplies, to bring them into rm'engagement with the 'bead and enclose the latter, as shown in Fig,:l0.

At the position of the stitcher shownV in the latter figure, pressure is remo-ved from aircylinder by the timer and the stitcher standardl revolves in sleeve |54 under the urginggof coil spring ll, to move the stitcher away from the drum, to its original position, as shown in Fig. l1.

Inthe stitching operation just described, -itis the large element 298 of the stitcher which is employed. Referring to Fig. 6, it will be seen that the direction of rotation of drum 2 and the direction o f movement of the stitcher are suchas to urge shaft It downward, so that pin 2% is contacted by limit screw 20 and shaft ltllA makes an angle with a radius of the drum, as indicated by the character a. It has been found that this angle should be of the order of 8. This urges stitcher element 208 constantly againstelement respective supply'rolls and placed on the drum insuccession. andthe chafer strips 242' and tread strips v'243 are thereafter taken from the storage rack and Vplaced' on the drum. Inthe placing of the tread on the drum, a centering device, 244, pivoted-on-"a brac'zket 24,6, on lthe-apron 24 for swinging-motion andf-having a, guide wheelV 241, will be employed, `as understood inthe art.

Thereafter, air cylinders"41:- are actuated to bring stitcher4 discs 44 into "contact with the tread'at the center;l thereof and screw -49 is fro- 'tated'so that-the respectivehdiscs 44 move in opposite directionsacross the treadwhile maintaining pressure thereon. As discs 44 pass. the high points ofthe central, thick band of the tread, the stitching pressure Vis likely to diminish if the rate of motion of the discs axially of the drum is maintained. Therefore, the switch 54 is provided to effect lowering of the speed of rotation of screw 49. When discs 44 reach the outer margins of the tread strip, limit switch 55 reverses air cylinders -41, so that discs 44 are lowered away from the drum, and screw 49 is rotated in the reverse direction to return the stitchers to their idle'postion centrally ofthe drum, whereupon rotation of the screw is stopped by a limit switch (not shown) At this point, the tread is trimmed, if necessary, and for such purpose any convenient form of trimmer may be employed. However, the present trend is to provide treadj strips Vof accurate dimensions, so that the need for trimmers is eliminated.

The next step is the turn-down of the third and fourth, or so-called "over-bead plies, which, up to this point, have been extending from the ends of the drum. The turn-down is initiated by roller 62 on spring stitcher unit 56, vwhich carries the plies half Way across the bead to the position' shown in Fig. l1, the drum rotating in a direction as shown in Fig. '1, as initiated by a foot pedal switch 248. Thereafter, air cylinder |1| is actuated to rotate standard |56 in sleeve |54, to bring the rim 2|| of end roller 201 of the stitcher into contact-with the plies, and motor ||9 is actuated to move the stitcher around the bead, in pressure contact with the outer ply, in a direction reverse to that of the first stitching operation by this stitcher. As seen in Fig. '1, the direction of rotation of the drum and the direction of movement of vthe stitcher are such as to swing shaft |89 upward until pin 206 is contacted by stop screw 202, in whichposition the axisl of shaft 89 is substantially aligned with a radius of drum 2. The combined effect of the direction of rotation of the drum and of the angular position of shaft |89is such that, during travel of the stitcher inwardly across 'the bead, element 208 of the stitcher, due to contact with the plies, recedes along shaft |89 against the pressure of spring 228, and the stitching operation is performed by the thus exposed rim or bead 2| of end element 201 of the stitcher (Figs. 12 and 13). This not only affords a more effective stitching operation for this particular phase of the process, but also enables stitching in close quarters, inwardly of the drum where theplies terminate, as shown Fig. 13. It will be noted that the inner ledge ofY the-` drinn rim is beveled,

"1Y0 as at 249, to provide more clearancefor the stitcher. f

The swinging adjustment of the rear stitchers about shaft 69, byr nuts 9|, to accommodate different sizes of drums, `lnecessitates a re-setting of stop screws 201,202 to maintain theproper limiting values of theangle of stitcher4 shaft |89 with respect tothe-drumradius.VK In Vorder to avoid the necessity for such adjustment,*the stitcher assembly may be mounted fr sliding motion to and from the drum, rather than swinging motion. ASuch van arrangement is shown in Fi'gs.15` and 16.v In Vthis modication,gthe shelf 13', correspondingto 'shelf 13, has itsvends extended beyondv end brackets l1|,"-as at25|,V and the extending ends V'are received for sliding motion 1in grooves 252, in slanted brackets253, secured by bolts"254`,"2561 to la base' pedestal casting 66 corresponding to base 66 in the firstdescribed arrangement. Grooves 252l may be conveniently provided by-a top vbar 251, secured by bolts 258 to bracket 253 and overhanging an inner rabbeted edge onv thelatter.

A central bracket 259 ofchannel form on base 66 Aslanted similarly tobrackets-253,- accommodates a bar"26 secured on the underside ofsheli` 13 for sliding motion; Shelf `313 and the stitcher mechanism carried Ythereby are moved parallel 'to grooves 252vand the'channel inbracket 259 by means of a screw 262 mounted for rotation ina bracket 263 bolted tothe end ofv bracket 259, the screw being threaded into central bracket 12, of shelf 13', and secured against^ axialr motion with respect to bracket '2.63 by collarsv 264 and 266.Y

It will be seen thatturning of Aadjusting screw 262`results in movement of shelf 13 parallel to the grooves 252 of brackets '253.- i The direction of grooves 252 is parallelto that ofthe axis' of shaft |89 when the latter isaligned with a radius of drum 2. Thereforein adjusting'the stitcher assembly Vto accommodate a different drum size, the angular relation Yof shaft 89 to the drum radius vis unchanged and no adjustment of limit screws 20|, 2021s necessary;v i t In the modification just described, no changes in those'v parts of theA stitcherasse'mbly above' shelf 13 are necessary. Shaft'69 and bar 1,1 still function to give a pair of vspaced. supports which maintain the stitcherunits againstturning with respect to shelf113'.

In Fig. 14 is shown a'modiedform ofA stitcher for use on the mountingof Fgs..2 and3.V In Vthis form,. theA shapeji'sV varied somewhat, the outer end beingless vin rd'iameter." and the rear vend greater indiameterthan'. the stitcher first described. v.Ithas beenfound byY experiment ythat noone shape ofl stitcher gives optimum performance for alltypes and sizes `of tire.l In particuf lar, it has been found-that the flaredshape shown in Fig. 14 performs better o n larger sized tires than does one similar in shape tostitcher |88.

While acertain preferred embodiment' of the invention has been shown and described-,the in- Vention is not limited thereby, since changes in the size, shape, and arrangement, for instance, ofl the variousparts 4may be resorted'zto .without departing from lthefspirit or scope of -theappendedclaims.

What is claimed is: g.

l. In combinatioma tire building drummounted' on a central'hub; a'ibead .applying element mounted onan upright; armon'a mounting slidable axially ofv the', said fdium, and telescoping Ameans located axially'onthe; drum'and 'axially on said element iorcentering said element vwhen in Yproximity to said drum.

Vfor rotation on said shaftand having ,a'portion lying substantially on the line o the axisof said yjournal mounting. r l

3*.KAstit/ol'1erV unit'rfor tirebuilding machines comprising a@f inirwnal, mounting, a crank arm journaled in saidhmounting, a'standard mounted for rotation on said crank arm, a sha-ft mounted onfsaid standard forswinging motion about an axis generallytransverse to said standard, and a stitcher tool mountedfor rotation'onsaid'shaft andV havinga portion lyingsubstantially on the iine Vof ythe axis of said fjournal'mounting.

A stitcher unitl 4for tire building machines comprising a-journal mounting, a stitcher arm mounted for rotation in said mounting, and a stitcher tool on said arm mounted iorrotation about an axis generally transverse to'the axis of said journal mounting, saidl'arm having a portion onset from the axis of said 'journal mounting and said tool having Ya portion'lsubstantially on the line of the axis of saidvjournal mounting. Y v5.7 A istitcher unitgfor Vtire building machines oomprisinga journa1 mounting, a stitcher tool mounted for rotation about an Vaxis generally transverse tothe axis 'of-said mounting. spaced fromthe end offsaid mounting, and having a portion substantially ontheline of the axis of saidmountingmeans rotatably mounted in said mounting and connectedto said stitcher too1,'and said `means having a `portionoiiset from Ythe line f the asis, Qfad mounting. c

A6. A'stitcherunitior tirebuilding machines comprising d anm element adapted for journaled mountingQmeans mounting a s titcher Vtool for rotation about arl-axis 'generally transverse to the journal Yaxis'of said mounting, saidtool having a portion on the line of'theVsaidjournalvaxis and spaced fromssaid-mounting,- and'meansl connesting the' said "element raniijsaid tool, saidM ietf termeans'having aportion'oiset fromtiie journal 'axisjgof' said mounting.

Y 7.. A` ancha unsinnig jbl-maine 'metisses' comprising 'an element v-adapt'eci vfor journald mounting, a stitcher tool, means mounting said tool for rotation aboutf anaxisgener'allv 'transverse fto the Ajournal of r said mounting, 'said toolhaving aportiononthelineof thesaid jour--v nal axis andV spaced Ifromjnsaii mounting,'meansl connecting the said `element Aandsaid tool, 'I said latter means having av portion `offset Lfrom said vj journal axis, and saidlnrfst-)mentioned Ymeansbeing mounted forflimited-'angular swing aboutan axis transverse to said journalaxis'fand axis'of rotation of vsaid tooh 8. A stitcher unit `for tire building machines to 'the comprising an Vrelement ladai'itedfor journaled mounting and thus Ydeiining an'axis of rotation, a stitcher tool Vspaced Vfrom said velement and having a portion on the line'ofV the rotation axis thereof, means mounting said tool -for rotation about an axis transverse to the'axis of said jour-Y Aof said other axes, Vand,means"connectingthe said tool and its mounting lWith the saidf ele- Y ment, said lattermeans having arportion offset "Shaft ,Y

16. A 'stitcher toolffor -ti'refbuilding machines 'fer 'relative dispolatementeaxial-lr .Qfhemount- Vingi'neans thereof. Y 1. r

arranged in tandem,u means.mounting Vsaiddatter elements for rotation, one-fofVVV said jrotatable,

elements being movable `axially of said means, resilient means urging theimovableelement to a normal position onA its mounting means, said mounting means arranged ikorflimitedfswinging motion about an axis transverse to the-axis of said iirst-mentioned. element, fand meansl connecti-ng the'mounting means ofi'said tool -withthe first mentioned element andrhavinga portion -off'- set nfrom the line of theaxisfoi j said'firstmentioned/element. Y u Y 10. A-stitcher unit for tire bui'ldingrmachines comprising a shaftya rstroller stitcher mounted on the shaft, Ya second-rollerstitcher mounted on the shaft', arranged for sliding motion along said shaft'resilient 4means normally urging said secondroller stitcher into contact with said first roller stitcher, meansfmounting said shaft for limited angular swingotsaid roller stitchers about an axis'transversetotheaxis o f said-shaft, said 'latter 'means adapted'for journaled mount-v ing on'an axis transier's'eto'ftle axis of said shaft and the'axis of'swing-f isai'drollers. i

11. A unitas in claimfio,'thef'meanslrnounting said shaft being substantiallifoset'fronitheaxis of said Ajonrfnaled'mounting.. A' l 12.4 `A stitch'er unit fortire building .machines comprising 'fa orank-armfastitcher support journaledin saidcra'nk arm, a sh'a'f-t pivoted on-fsaid Support for swinging motion about vanV laxis transverse yto the'axisof turning of said-support, and a roller stitcher mounted for rotation-ones'aid shaftQ. n u I l i 15,3. A stitcher unit for tire buildingmachines comprising a crank arm, a sti-toher-support'journaled -in saidvcranl; arm, a--shait ypivoted onV said support for limited Aswinging motion *about an axis transverse to theaxis'oturning'ofsaid1support, ga first stitcher tool mounted vfor rotation on'said shaft, yanda-second stitcher -toolq mounted for I rptation'l-on -said shaft, located between the saidirst stitcher tool "and-the pivoted end of the shaft, and arranged forfsliding motion along saidsehait. i 14. Inv a stitcher'unit 'asinaclaim'ljmeansto rotatey said supportand resilientfmeans opposing rotationV of said support;V i

-15.-In a-stitcherunit asinLClaim yi3;"ifesiliei'it means opposing lsliding vmotion 'ofi said lsecorid stitcher "tool toward 'the fpivoted eii'clfof `s'aid comprising a shaft, a first'stitchertoolmonted for rotation on saidshaft, 'fand alv second-"stitch'r tool Afreely mounted 'for 5 rotation `on 'said 4`shaft anderer sliding motion-aiong'saidfnafa 17,'5A stitcher ftool *Comprising 1a supporting arm, da shaft pivoted o'n vsai'd `Jar'in Ifor limited swinging motion land -extndingfgenerally trans-h verseiy 'of said shaft,anrstsutenertoormuiite for" rotation on said' shaftfand a-'fseco'iircl''stitche'r tool freely 'mounted "fo'rrtationon s'aid 'shaft and forsiiding motion aiding ns'a-ifdsnft,

18, In combination, a vfoire 4building "dnim fa supportior 'a'stitcherun g a crankarin AS15 d from said' drum and jbiirriaid for rotation'n 13 Said support on an aXis generally tangentially of said drum, an arm journaled in said crank arm on an axis generally parallel to but spaced from the first-mentioned axis, a shaft pivoted on-said arm for limited swinging about an axis generally 5 transverse to the other two said axes, a rst stitcher mounted for rotation on said shaft, a second stitcher mounted for rotation on said shaft and slidable therealong, and spring means urging said second stitcher toward said rst 10 stitcher, said stitchers being positioned to contact a rim of said drum.

HORACE D. STEVENS.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,415,724 Sloman May 9, 1922 1,677,871 Putt July 17, 1928 2,161,117 Wikle June 6, 1939 2,381,379 Stevens Aug. 7, 1945 2,409,974

Breth et al Oct. 22, 1946 

2. A STITCHER UNIT FOR TIRE BUILDING MACHINES COMPRISING A JOURNAL MOUNTING, A CRANK ARM JOURNALED IN SAID MOUNTING, A STANDARD ON SAID CRANK ARM, A SHAFT MOUNTED ON SAID STANDARD FOR SWINGING MOTION, AND A STITCHER TOOL MOUNTED FOR ROTATION ON SAID SHAFT AND HAVING A PORTION LYING SUBSTANTIALLY ON THE LINE OF THE AXIS OF SAID JOURNAL MOUNTING. 